The present invention relates to a semiconductor device having a ceramic package incorporated with a heat-radiator, and more particularly, to a semiconductor device in which a heat-radiator is bonded to a package body by a resin film.
To dissipate effectively a heat generated in a semiconductor chip during the operation, a radiator or heat sink is attached to the ceramic package body in which the semiconductor chip is installed. The attachment of the radiator to the package can be conducted by screw means or solder bonding means. Further, to increase the efficiency of the attaching work and to minimize the adverse influence on the ceramic member of the package during the attaching work, a structure in which the radiator is attached to the package body by using a resin film as adhesive has been proposed by N. Honda et al. in U.S. Pat. No. 4,340,902. The proposed prior art structure, however, cannot achieve a sufficient attaching strength, that is, a sufficient bonding strength between the radiator and the package body, because the resin film as adhesive is adhered to a molybdenum surface of a composite metal plate fixed to a ceramic member of a package body. On the other hand, if the structure is conducted by conventional process steps in which a nickel plating is followed by a gold plating, the gold plating film is inevitably provided on the metal plate, and the resin film as adhesive is adhered to the gold plating film. In this case, also a sufficient bonding strength cannot be obtained. Further, if, in the prior art structure, a epoxy resin which shows a high hardness nature after heating cure is used, cracks are apt to be produced in the adhesive resin when a repetition of change in environment temperature between high and low levels, that is, temperature cycles is affected to the device. Consequently, a high reliable device could not be obtained.